A lack of money to assess how to modernize the ground-based missile leg of the strategic nuclear triad could prove controversial on Capitol Hill.

The Defense Department budget request for the coming fiscal year omits funds that were to have allowed the Air Force to study the prospects for a new intercontinental ballistic missile to eventually replace today's Minuteman 3 arsenal, according to a senior service official.

"To my knowledge, there's no funding in [fiscal 2012] for a future ICBM," Marilyn Thomas, budget deputy to the Air Force comptroller, said at a Monday news conference as the federal request was delivered to Congress. A lack of budgeted funds to assess how to modernize the ground-based missile leg of the strategic nuclear triad could prove controversial on Capitol Hill, particularly among Republicans. A crucial sweetener for winning Senate GOP votes in favor of ratifying a new U.S.-Russian arms control treaty late last year was the Obama administration's commitment to modernizing nuclear warheads and delivery platforms.

The fiscal 2012 budget includes $197 million for research and development on a new Air Force long-range bomber -- potentially either manned or unmanned -- that would be ready for fielding in the mid-2020s. That is an early installment on $3.7 billion to be spent in developing the nuclear-capable aircraft over the next five to six years. Ultimately, 80 to 100 of the aircraft are to be built, defense officials said.

The funding plan also features $1.07 billion to develop a new ballistic missile submarine to replace today's Ohio-class vessels. The so-called "SSBN(X)" in December entered an initial developmental phase in which its design specifications will be honed.

These items are part of a $671 billion Defense Department budget request for the new fiscal year, which begins on October 1. In an unusual twist, next year's military spending plan is being delivered to Congress before lawmakers have passed defense appropriations for fiscal year 2011, which began last October. The federal government is operating on a continuing budget resolution -- based largely on fiscal 2010 funding levels -- that expires on March 4.

The Defense Department comptroller, Robert Hale, said on Monday that there is ICBM funding in the budget for fiscal 2012 and subsequent years.

"There's ICBM modernization money," Hale said in response to a reporter's question at a news briefing prior to the Air Force session at which Thomas spoke. "I don't have on top of my head the numbers. But there is a fairly aggressive modernization program of our ICBMs, our strategic forces."

Hale's office said Wednesday, though, that he was "referring to funding to sustain and upgrade the current ICBM fleet, rather than suggesting there was funding for new ICBMs."

The comptroller "concurs with what the Air Force spoke to in their briefing," his office said.

The Pentagon last spring declared in its Nuclear Posture Review -- a major assessment of strategy, forces and readiness -- that while "a decision on any follow-on ICBM is not needed for several years, studies to inform that decision are needed now."

The nation today fields 450 Minuteman 3 nuclear-armed missiles at three bases in North Dakota, Montana and Wyoming. Under the New START agreement, which entered into force on February 5, Washington will retain no more than 420 deployed Minuteman 3s, each armed with a single nuclear warhead.

The United States and Russia have seven years to complete reductions in their nuclear forces under the accord, which caps fielded strategic warheads at 1,550 and limits deployed strategic delivery systems to 700.

The Minuteman 3 first entered the force in 1970 and production of the missile ended eight years later. The system has undergone a number of upgrades over the years but must be replaced by 2030, Air Force officials say.

However, neither Thomas nor her uniformed counterpart, Maj. Gen. Alfred Flowers, were able to specify a time frame by which the Air Force must launch a formal program to procure a new ICBM or say when such a system would be fielded.

A spokesman for the service also was unable to offer specific dates, but did indicate there is no formal effort for a future ICBM at this time.

"The [Air Force] is executing a service life-extension for the Minuteman 3 program, extending the service life to 2030," said spokesman Andre Kok. "There is currently no program of record to develop a Minuteman 3 follow-on."

The initial study of potential technology alternatives for replacing today's ICBMs was to begin in fiscal 2011 and continue into 2012, according to the Nuclear Posture Review.

"This study will consider a range of possible deployment options, with the objective of defining a cost-effective approach that supports continued reductions in U.S. nuclear weapons while promoting stable deterrence," the review report stated.

The ICBM assessment appears to have at least begun over the past year, but it is unclear whether or how it might continue this year or next without the anticipated funding.

The Obama administration in November submitted to Congress an update of its plans for nuclear force modernization that included projected budget figures for studying options for building an ICBM follow-on system.

"Preparatory analysis" for the new land-based missile program "is in fact now under way," the so-called "Section 1251 Report Update" stated last fall.

The initial ICBM analysis, called a "Capabilities-Based Assessment," was funded at roughly $26 million per year, according to the update report. It echoed the April 2010 posture review's description of the new assessment as exploring a variety of future ICBM deployment options.

To maximize a president's decision-making time during a future crisis, ICBMs could be fielded differently to make them less exposed to potential enemy targeting, the Nuclear Posture Review stated. The idea would be to eliminate any temptation for a hasty nuclear launch out of fear that Washington must either use its weapons or risk losing them.

The Pentagon would explore "new modes of ICBM basing that enhance survivability and further reduce any incentives for prompt launch," according to the posture report.

Potential alternative basing options for the future ICBM could include mobile missiles, according to defense sources. Today's arsenal of Minuteman 3s is fielded in fixed underground silos, though road-mobile missiles were considered briefly in the 1980s as a less vulnerable alternative.

Contrary to statements in the 1251 report update, the $26 million to undertake the initial capabilities assessment was not funded during the current fiscal year, nor is it included in the 2012 request, according to one budget analyst who asked not to be named in discussing the militarily and politically sensitive matter.

"Despite promising to spend $26 million per year [on the] capabilities-based analysis, no Air Force funds were requested in FY 11 and FY 12 for that purpose," the analyst told Global Security Newswire.

While obscure to most Americans, the administration's update report on nuclear modernization played a key role in wooing Senate Republican fence-sitters during last year's debate over New START ratification.

The Obama team used the document to illustrate the aggressive steps it would take in the near term to keep the aging nuclear stockpile viable and update the bombers, ICBMs and submarine-launched missiles that carry atomic warheads.

A key GOP leader in the debate -- Senate Minority Whip Jon Kyl (R-Ariz.) -- remained unconvinced. In late November Kyl wrote a memo to fellow Republicans casting doubt on whether the administration intended to launch a new ICBM effort at all, among other concerns.

"We think it important to understand what the administration intends when it suggests that a decision regarding a follow-on ICBM must be guided, in part, by whether it 'supports continued reductions' in U.S. nuclear weapons," Kyl stated in the letter, also signed by Senator Bob Corker (R-Tenn.), who later voted in favor of New START. "One logical inference from this criterion is that a follow-on ICBM is no longer needed because the U.S. is moving to drastically lower numbers of nuclear weapons."

Vice President Joseph Biden said last year the administration was so committed to maintaining an up-to-date arsenal that it would fund its plans for nuclear modernization regardless of whether the Senate approved New START. The Senate ultimately ratified the accord in a 71-26 vote that included 13 Republicans.

In its resolution of ratification, the Senate included a requirement that President Obama move forward in updating the nuclear triad, though it did not dictate time lines.

Three days before his secretary of State exchanged ratification documents with her Russian counterpart, Obama assured the U.S. Senate that he would honor his pledge.

"I intend to (a) modernize or replace the triad of strategic nuclear delivery systems: a heavy bomber and air- launched cruise missile, an ICBM, and a nuclear-powered ballistic missile submarine (SSBN) and SLBM; and (b) maintain the United States rocket motor industrial base," Obama stated.

Rocket motor production is required for building both sea- and ground-based strategic missiles.

According to the 1251 update report, the Pentagon intended to kick off the next preparatory step in the process -- a formal "Analysis of Alternatives" for filling the new ICBM military requirement -- in fiscal 2012. This would build on the Capabilities-Based Assessment by further narrowing the scope of technology options for the future missile.

By fiscal 2014, the analysis was to be complete, at which point the Defense Department would "recommend a specific way-ahead for an ICBM follow-on to the President," the modernization update report said.

The Pentagon last fall was unable to estimate development and procurement costs for the future ICBM because of "the inherent uncertainties about missile configuration and basing prior to completion" of the Analysis of Alternatives, the report stated.

"However, [the Defense Department] expects to be able to include funding for [research and development] for an ICBM follow-on system in the [fiscal] 2013 budget request, based on initial results" from the analysis, the report said.

Clarification: This article was updated to include an explanation of Defense Department Comptroller Robert Hale's remarks that his office provided on Wednesday.